Disposable diaper has been used in order to handle urine and feces conveniently. At present the amount of disposable diaper waste increases gradually. Incineration and landfill have been the only ways to dispose of disposable diapers. However, if they are disposed by landfill, decomposition will take more than one hundred years. In addition, another way of dispose incineration has caused air pollution. Therefore, it is necessary to study recycling process for disposable diaper since plastic and wood fibers of diaper are useful materials to recycle. In this study, pulping condition of disposable diaper waste was studied in order to effectively separate the components. Recovery rates of plastic and fibers were analyzed under different pulping conditions. It was found that optimum pulping consistency was 5%, time was 60 minutes, temperature was 50°C, and cut size is 21 cm×21 cm. The recovery rate of plastic and fibers can be achieved above 70% under the optimum pulping condition.

Lee T.J.,Korea Advanced Institute of Science and Technology | Nam Y.S.,Kangwon National University | Park J.E.,Kangwon National University | Jo J.H.,Kangwon National University | And 2 more authors.Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry | Year: 2015

Disposable diaper waste is consisted of plastic, fiber, and SAP (Super Absorbent Polymer). They are valuable to be used as raw materials of other products including plastic blocks and pulp mold. Nevertheless, disposable diaper waste have been disposed by landfill and incineration without recycling. Due to strict environmental regulations it is necessary to develop fractionation technique to recycle the disposable diaper waste. In this study the fractionation technique using pilot-scale stock preparation units was investigated. Process for separation of plastic and fibers from disposable diaper waste was composed by the combination of pilot-scale pulper, drum screen, screen and cleaner. Recovery rate of plastics and fiber was checked according to the various operating conditions. In drum screen, recovery rate of plastic was high when the cut size of disposable diaper waste was 5 cm × 5 cm. The highest recovery rate of fiber was achieved with 0.3 mm slot screen. It is important to control the neutral state of SAP for improvement of recovery rate of fiber since SAP can be swelled easily in water. Therefore SAP can be controlled efficiently by the addition of calcium chloride into the pulper. Consequently recovery rates of plastics and fibers were over 90 and 80% under the optimum pilot operating conditions.

This study aims to suggest wastewater treatment options for diaper recycling by identifying characteristic analysis of wastewater from diaper recycling process and efficiency evaluation of wastewater treatment units. The wastewater characteristic analysis showed that the concentration of organic pollutants and ionic materials were very high comparing to seawater. Through the investigation of similar wastewater treatment, six treatment units were identified to reduce pollutants. It is found UF(ultra-filtration), DAF(dis-solved air flotation), fenton oxidation, electro-coagulation and chemical-coagulation are effective in reducing organic pollutants while membrane system and ion exchanger are effective in reducing ionic materials. Even though the target of water quality should be secured in terms of managing organic pollutants level, the application of treatment unit for reducing ionic material needs lots of considerations. This result suggests that reuse of pulping wastewater after controlling organic pollutants is better than direct discharge of pulping wastewater. To select the appropriate wastewater treatment unit, an economic analysis about operation condition, wastewater flow, cost, efficiency should be considered.